1. Field of the Invention
The present disclosure concerns data processing comprising a data transfer between memories, more specifically a data transfer achieved through the use of a Direct Memory Access (DMA) device.
2. Description of the Related Art
In certain applications such as video, a mass storage device, hereinafter called the external storage, stores the data which are to be processed by a processor using a given algorithm. In the conventional method, the processor has access to a processing memory, hereinafter called the internal memory, which is directly associated with it and from which it retrieves the data to be processed. Therefore the data are first transferred from the external storage to the internal memory before being processed by the processor.
It is conventional to use a DMA device to perform the data transfer between the external storage and the internal memory. A DMA device allows direct data transfers between an external storage and an internal memory associated with a processor, without requiring the intervention of the microprocessor, with the notable exception of initiating and concluding the data transfer. Thus the DMA device reduces the processor load, because the data transfer may then be achieved almost without processor intervention. In this type of data transfer, the data, which are stored in a given data format in the external storage, are stored using the same format in the internal memory.